When a machined bore in a piece of equipment becomes worn due to high cyclic load, old age, lack of grease or some other factor, they become egg shaped or worn so they no longer function as intended. They can be economically repaired by building up the bore slightly undersize with weld and machining back to the proper diameter. For example, a machined bore in a heavy gear wheel may become so worn that the bearing within the bore no longer fits tightly within the bore and this can lead to machine failure. These pieces of equipment can be repaired by using a bore welding technique that adds material to the inside surface to build up the worn surface of the bore until it becomes undersized. A bore welder uses a rotating and stepping torch, along with the MIG process to build up the surface of a worn bore by depositing contiguous weld beads around the bore's circumference. Once the bore has been augmented, the piece is then re-bored to the proper size and the bearing can be reinserted. This operation can be performed in a workshop but is often performed in the field where swift repairs to critical equipment are necessary.
There are a variety of bore welding machines in the market place. These machines are priced into the tens of thousands of dollars making the possession of such equipment difficult for many small businesses. Therefore, there continues to be need for a lower cost “entry level” bore welder that possesses the automated features of larger machines such as an adjustable step feature.